Analysis of Vancomycin Dispatch Times

Brian Gulbis

March 24, 2017

Distribution

In all of the following figures, values where the scheduled collection time occured > 1 hour prior to the order time were removed (n = 44). It is unclear exactly why the the scheduled collection time for these orders was back-dated to be prior to the time of ordering.

Histogram of difference between dispatch time and scheduled collection time

It is clear that Stat orders dispatch immediately, but Routine and Timed Study are much more variable, with most dispatching 1-3 hours before the scheduled collection time.

Distribution of the difference between dispatch time and scheduled collection time in all HVI units

Summary measures for the time from dispatch to scheduled collection

minimum q1 median mean q3 maximum na
-3.017 0 0.7833 1.709 1.783 33.55 33

Summary measures for the time from dispatch to scheduled collection by collection priority

priority minimum q1 median mean q3 maximum na
Routine -3.0170 0.25000 0.2667 2.0350 2.767 23.80 12
Stat -0.8000 -0.01667 0.0000 0.7422 0.000 24.28 7
Timed Study -0.4833 0.78330 1.7670 2.0790 2.183 33.55 14

Distribution of dispatch time by day of week

Distribution of dispatch time by hour of day

Labs ordered > 72 hours in advance of collection were removed.

Histogram of difference between order time and dispatch time

Distribution of difference between order time and dispatch time

Correlation Assessment

Time between order to scheduled collection and order to dispatch. Data with order to scheduled collection of > 72 hours were removed. Values where the scheduled collection time was prior to the order time were removed.

There is a strong correlation between the time from order to scheduled collection and the time from order to dispatch.

Correlation between the time from order to scheduled collection and the time from order to dispatch

estimate statistic p.value parameter conf.low conf.high method alternative
0.963 189.486 0 2804 0.96 0.966 Pearson’s product-moment correlation two.sided

Time between order to scheduled collection and dispatch to scheduled collection

There is little correlation between the time from order to scheduled collection and time from dispatch to scheduled collection. This suggests that the dispatch time is triggered by the scheduled collection time, regardless of how far in advance the lab is ordered, with the exception of Stat orders which dispatch immediately.

Correlation between the time from order to scheduled collection and time from dispatch to scheduled collection

estimate statistic p.value parameter conf.low conf.high method alternative
0.316 17.663 0 2804 0.283 0.349 Pearson’s product-moment correlation two.sided

Time between dispatch to scheduled collection and scheduled to actual collection

There is no correlation between the amount of time prior to scheduled collection that the task dispatched and when the lab was actually collected.

Correlation between the amount of time prior to scheduled collection that the task dispatched and when the lab was actually collected

estimate statistic p.value parameter conf.low conf.high method alternative
-0.083 -4.112 0 2431 -0.122 -0.044 Pearson’s product-moment correlation two.sided